Pliers



7- A. ICRUICKSHANK:

PLIERS Fil ed Oct. 5, 1955 INVEN TOR ALEXANDER GRU/CKSHANK ATTOR N EY? Patented Jan. 5, 1937 2,066,718 l PLIERS Alexander Cruickshank, Clayburn, British Columbia, Canada Application October 5, 1935, seria N01335:;

" 3 Claims.

My invention-relates to improvements in pliers.

The objects of the invention are to provide a plier in which a progressive increase in gripping purchase is obtained as the handles are drawn to- 5 wards each other, whereby nuts and bolts may be easily gripped and turned; to provide means whereby adjustable spacing of the jaws may be effected by a slight thumb pressure while holding both handles in one hand; to provide a selfaligning jaw which is not dependent on a pin for a fulcrum, and to'provide %1 easy spring opening of the plier.

The invention consists essentially of a pair of pliers having an adjustable fulcrum, said pliers having one jaw integral with a handle and another jaw operated from a second handle by a compounded leverage, and a link connecting the main fulcrum of the compound leverage to the adjustable fulcrum whereby pressure applied to the handles serves to prevent movement of the adjustable fulcrum, as will be more fully described in the following specification and shown in the accompanying drawing, in which:-

Fig. l is a general view of the pliers adjusted for gripping small articles.

Fig. 2 is a general view, partly fractionated, of the pliers adjusted for gripping large articles such as valve hoods, large nuts etc.

In the drawing like characters of reference indicate corresponding parts in each figure.

The numeral I indicates generally a member made up preferably of pressed sheet steel folded longitudinally to form a substantially T-shaped member having its upper portion serving as a 35 jaw 2, its intermediate portion forming a bearing 3 and its lower portion a handle 4.

The jaw portion 2 of the member I. is slotted as at 5 and is fitted with a jaw insert 6 consisting of a strip of T steel having its base serrated as at I to provide a gripping surface and its web cut away as at 8 to form a tongue which .is riveted over at its free end as at 9 to loosely yet securely hold the jaw insert in the folded upper jaw portion 2 that it may rock and adjust its position about the curved inner face I of the fold. The bearing 3 consists of a diagonal slot II, the lower margin of which is corrugated to define a plurality of semi-circular notches I2. Pivotally engaging .any of the notches I2 is a fulcrum pin I3 which passes through a second jaw member I4 which too is preferably made of sheet metal folded upon itself in the same manner as the member I, this member supports at its upper end a jaw insert I5 similar to that 55 previously described, except that it is immovably secured in position between the folds of the metal. The lower end of the member I4 is pivotally connected by a pin I6 to a second handle I! also of U-shaped section.

The handles 4 and I1 are connected together 5 by a toggle I8 consisting of two links I9 and 20 connected together at their inner ends by a pin 2I, and connected at their outer ends to the handles 4 and H by pins 2IA. The links I9 and 20 are angularly disposed to each other at all 10 times and the apex of the angle so formed is towards the free ends of the handles 4 and IT. The pin 2| connecting the links together also forms a connection with a link 22, which link is connected at its upper end by the fulcrum pin l5 l3 about which the member I and the second jaw member I4 swing.

A wire spring 23, shown in dotted line in Figure 2, is suitably inserted into the member I and passed around the pin 2IA of the handle 4 to urge the lower end of the jaw insert 6 inwardly and to urge the inner end of the link 20 downwardly, so that the pin I3 is held firmly within the selected notch I2 and the pin 2L is retained at a predetermined spacing from the handle 4. A further spring 24, likewise shown in dotted line in Figure 2 is wound around the pin I6 and is so arranged as to urge the free ends of the jaw member I4 and the handle I'I outwardly. The springs urge the handles and the jaws apart and the spring 23 through its downward pressure upon the link 20 also urges the link 22 downwardly, so that the fulcrum pin I3 is held in position within its notch I2 while in normal use.

When the jaws are set about a nut or other device to be gripped and the handles are squeezed together the jaws close into position upon the nut. It will be observed that the angle between the link 20 and the link 22will remain constant when set in any position due to the pin I3 being engaged in one of the notches I2, but that the link I9 will in its tendency to close inwardly towards the link 22 exert a thrust upwardly and outwardly through the upper part of the handle H to the pin I6, thus compounding the leverage of the handle II, so that with a relatively slight pressure upon the handle great force will be applied to the nut.

When it is desired to adjust the spacing between the jaws, a slight upward thrust being applied under the toggle I8 will release the pin I3 from engagement with its notch I2 when movement of the handles will bring the desired notch into register with said pin. This adjustment can be conveniently made by the hand supporting the pliers.

What I claim as my invention is:

1. A pair of pliers comprising a jaw member having an integral handle, a second jaw member pivotally connected to the first, a handle connected by a pivot pin to the second jaw member and connected by a toggle to the handle of the first jaw member, the pivotal connection between the first jaw member and the second jaw member consisting of a slotted member having a plurality of notches in which the pin is selectively engageable and a link connecting said pin intermediate the length of the toggle.

2. A pair of pliers comprising a jaw member having a jaw at one end, a handle at the opposite end, and a lateral projection intermediate its length, said lateral projection having a slot with a plurality of notches along one side, a second jaw member having a pivot pin adapted to selectively engage the notches, a second handle pivotally connected to the second jaw member, a toggle connected at its outer ends to the handles and a link connecting the pivot pin intermediate the ends of the toggle, said toggle being so disposed that its apex is directed towards the free ends of the handles.

3. A pair of pliers comprising a jaw member having an integral handle, a second jaw member pivotally connected to the first, aihandle connected by a pivot pin to the second jaw member and connected by a toggle to the handle of the first jaw member, the pivotal connection between the first jaw member and the second jaw member consisting of a slotted member having a plurality of notches in which the pin is selectively engageable and a link connecting said pin intermediate the length of the toggle, and spring means for urging the h'andlesapart and to impart a strain upon the link whereby the pivot pin is retained in its selected notch.

ALEXANDER CRUICKSHANK. 

